1. Field of the Invention
The present invention relates to an interface circuit used for signal transmission between circuits having different reference potentials. It also relates to a power conversion device and a vehicle-mounted electric machinery system.
2. Background Art
An example of conventional interface circuits is disclosed in Patent Document 1. This conventional interface circuit includes a current source and a resistor, wherein a pulse signal inputted from a circuit with a first reference potential is transmitted as a pulse signal having a second reference potential different from the 1st potential by switching the direction of current through the resistor. In this way, signal transmission between circuits with different reference potentials is carried out without employing any externally attached components such as an optical isolator.
Patent Document 1: JP Patent Publication (Kokai) No. 9-46145 A (1997)